Conference calls reduce the need to travel, and consequently save money and time. In the past, people participated in conference calls via a telephone, but today many different types of processing devices, including desktop and laptop computers, tablet processing devices, slate processing devices, and smartphones can send and receive audio signals, and thus may be used for conferencing. Because such processing devices may have a display, user interfaces have been developed which simplify setting up and/or participating in a conference call. Users of such processing devices typically wear headsets, headphones, or earbuds in conjunction with a microphone to send and receive voice signals.
It is not uncommon to receive invitations to participate in multiple conference calls that are scheduled at times that overlap one another. Typically the invitee must turn down one of the invitations, even though the invitee may want to participate in the call, and may know that the call will nevertheless take place at the requested time irrespective of whether the invitee accepts or rejects the invitation. A participant in a conference call may spend 95% of the time listening, and 5% or less of the time speaking. However, not knowing exactly when the invitee may be expected to speak, or may desire to speak, requires that the invitee listen to the entire call, diminishing his ability to participate in multiple conferences simultaneously.
Communications that occur via electronic devices are typically monaural; therefore, the voices of the participants in a conference generally sound as if they are emanating from the same location. In a conference call with a small number of participants where each participant may know the others, and may recognize the others' voices, monaural audio streams may be satisfactory. But as participants in a conference call begin to talk simultaneously, as frequently happens as a discussion gains momentum, communications quickly become indecipherable as listeners cannot discern who is saying what. Many conferencing systems attempt to improve this situation by providing participants with only the voice signals of the most active speaker, and those of the loudest participant attempting to interrupt the active speaker. This approach, however, effectively limits the conference to one or two speakers and tends to prioritize loud and persistent speakers.
For practical purposes, it would be extremely difficult, if not impossible, to listen to concurrent conference calls using the same communications device, because the audio signals generated in each conference would sound as if they were emanating from the same position. Consequently, it would be difficult or impossible for the participant to intuitively distinguish which audio signals were associated with which conference.
Studies have established that the human brain can process multiple concurrent audio signals in a stereo audio environment much easier than in a monaural audio environment. Since many communication devices today, including many smartphones, are capable of providing a stereo signal to an output port, it would be beneficial if the audio signals associated with multiple simultaneous conference calls could be generated in stereo, and placed at different aural positions such that a participant in multiple concurrent conference calls could easily and intuitively distinguish those audio signals emanating from one conference call from the audio signals emanating from another conference call. This would allow a participant to participate in multiple concurrent conference calls, and relatively easily distinguish what is being said in each conference call.